Combined explosion or internal-combustion and compressed-air engine.



P. NOLET. COMBINED EXPLOSION OF. INTERNAL COMBUSTION AND COMPRESSED AIR ENGINE. APPLICATION FILED SBPT.10, 1912.

1,090,561. Patented Mar.17,1914.

Witnesses; In/ventar:

4/1. A Jorney.

PAUL NOLET, OFBRUSSELS, BELGIUM.

COMBINED EXPLOSION OR INTERNAL-COMBUSTION AND COMPRESSED-AIR ENGINE.

Specification of Letters Patent.

Patented Mar. 17, 1914.

Application filed SeptemberlO, 1912. Serial No. 719,594.

To all whom it may concern Be it known that 1, PAUL NOLET, a subject of the King of Belgium, residing at No. Boulevard Militaire, Brussels, in the Kingdom of Belgium, have invented a certam new and useful Improvement 111 Combined Explosion or Internal-Combustion and Compressed-Air Engines, of which the following is a specification.

This invention has for its object to increase the efliciency of explosion or internal combustion engines while at the same time dispensing with the necessity for cooling the walls of their cylinders.

It consists broadly in producing preliminary work by a portion of the force generated by the explosion or combustion of the gaseous mixture at the moment at which this takes place and before it moves the piston, this preliminary work diminishing the initial pressure and consequently the initial temperature in the motor; the quantity of energy thus expended is recuperated and employed for actuating the piston, the pressure of the exhaust gases being also caused to cooperate in this if desired.

lVith this object, the explosion or internal combustion engine is combined with a compressed air engine in such a manner that their respective compression chambers are separated by a movable wall and their pistons, which are integral one with the other, effect their compression strokes simultaneously. At the moment of explosion or combustion this force acts upon the movable wall which it displaces toward the interior of the air chamber in such a manner as to reduce its volume and consequently impart an excess compression to the air contained therein. As soon as the two coupled pistons begin to move the expansion commences simultaneously in the two cylinders and by virtue of the well-known properties of compressed air the work absorbed by the air during the excess compression will be returned entirely by the compressed air engine, the expansion necessarily continuing therein to atmospheric pressure. The displacement of the movable wall, in increasing the volume of the explosion or combustion chamber, diminishes the final pressure of the burnt gases, but this defect can be compensated for by conducting the exhaust gases into a chamber arranged beneath the piston of the compressed air engine so that it may act upon the lower face of this pisserving both for suction and exhaust.

ton during its following stroke; by this means the motor is compounded.

A constructional form of the compound motor is represented in vertical section in the accompanying, drawings, Figures 1 and 2 showing the utilization of the exhaust gases and Fig. 3 the arrangement in which these gases are not utilized.

In these figures 1 is the cylinder of the explosion or internal combustion engine and 2 the piston. The cylinder 1 is surrounded by the cylinder 3 of the compressed air engine which is provided with an annular piston 4- connected with the piston 2 in such a manner as to render it integral therewith.

The two combined engines work with a fourstroke cycle. Above the cylinders 1 and 3 a cylindrical chamber is divided into two compartments 5 and 6 by a movable partition 7 presenting the form of a piston the downward displacement of which is limited by a shoulder 15. The lower compartment 6 constitutes the compression and explosion or combustion chamber of the central engine and is provided with an exhaust valve 8; the upper compartment 5 constitutes the compression chamber of the air engine and it is provided wit-h a valve 9 A conduit 10, formed between the outer wall of the chamber 5, 6 and the inner wall of a jacket 11, places the compartment 5 in communication with the cylinder 3 of the air engine. This conduit may extend over a large part of the periphery of the chamber 5, 6. The valves 8 and 9 are both controlled mechanically by a cam shaft or other appropriate member actuated by the crank shaft of the motor. The fuel admission valve is not shown. 1n Figs. 1 and 2 the exhaust conduit 12 for the burnt gases conmiunicates with the cylinders l and 3 at their lower part in such a manner as to bring these gases beneath the pistons 2 and 4. The lower part of the cylinder is also provided with an exhaust conduit 13 with valve 14: mechanically controlled like the valves 8 and 9.

This engine operates as follows: At the commencement of the suction stroke of the pistons 2 and 4 the parts occupy the positions represented in Fig. 1, the movable partition 7 resting on the should-er 15. During the compression stroke the gaseous mixture is compressed in the chamber 6 beneath the partition? while the air is compressed in the chamber 5 above this partition. The proportions of these chambers should be such that the compression of the air is sufficient to cause the partition 7 to remain in place. hen the gaseous mixture is ignited, the force developed by the explosion or combustion acts upon the movable partition instantaneously, that is to say, during the increase of. pressure resulting therefrom and before this pressure moves the piston 2, the crank of which at this moment is located at the dead center or is approximately at that point. A portion of the excess pressure being thus converted into work as soon as it is produced in lifting the partition 7, the temperature and the pressure in the chamber 6 is kept lower than in ordinary engines. The ascent of the partition 7 produces an excess pressure of the compressed air in the chamber 5 and during the driving stroke of the compound piston this air expands in acting upon the piston t while simultaneously the pressure created in the chamber (5 acts upon the piston 2.

Fig. 2 shows the position of the parts during the driving stroke. The pressure in the central engine is necessarily always higher than the pressure in the compressed air engine during the whole of the driving stroke by reason of the differences of expansion arising from the displacement of the partition 7 The upward stroke and the position occupied by the partition 7 will be automatically regulated but will nevertheless be limited mechanically by the construction which varies with the type of motor required and the conditions imposed.

In the fourth phase of the cycle the air of the air engine is exhausted through the valve 9 and if the expansion of the gases of the central engine is utilized (Figs. 1 and 2) instead of these gases escaping directly into the atmosphere as in Fig. 3 they will pass through the conduit 12 into the cylinders 1 and 3 and complete their expansion in acting upon the lower face of the pistons 52 and 4:. These gases are exhausted through the valve 14: during the return or suction stroke of these pistons. This valve 14 closes only during the exhaust stroke proper.

In order to obtain the maximum of work with compressed air during the explosion or combustion, it is of course essential (the strokes of the pistons being equal) that the area of the air cylinder should be greater than that of the central cylinder. The ratio between the area of the cylinders may advantageously be as 9 to 1 approximately thus when the cylinders are arranged other than concentrically the ratio between the diameters will be 3 to 1 or when arranged concentrically as shown in the drawings, approximately 4 to 1.

The movement of the piston 7 at the moment of ignition of the gases permits of work bein stored without a very high temperature obtaining in the combustion chamber. It is obvious that the arrangement can be such that this temperature will not exceed a predetermined degree.

From the foregoing it follows that it is possible by means of the invention to store during the explosion orcombustion period a quantity of energy which is entirely returned to the motor; furthermore, the instantaneous absorption and conversion into work of this energy serves to keep down the initial pressure and consequently the initial temperature in the central engine. If, in point of fact, the theoretical efiiciency is reduced, the practical efliciency is increased because the method of diminishing the tem-' perature is not as prejudicial to the theoretical cycle as the usual method of cooling by water circulation. The exchanges of temperature between the central engine and the exterior are far smaller than in ordinary engines and take place largely in communicating the heat units to the air of the outer engine which has the advantageous result of raising the expansion curve of the compressed air.

The expansion of the compressed air being always complete, the temperature of the ex haust air will be approximately equal to that of the atmosphere. The outer walls of the air cylinder will never be very hot. The inner cylinder will also benefit from the great fall of temperature accompanying the expansion of the compressed air and the central piston will work as well as if the cylinder was cooled by any of the known cooling means.

In small motors such as those of motor vehicles it is not essential to utilize the expansion of the exhaust gases and the arrangement illustrated in Fig. 3 can be employed. In the case of powerful engines the cylinders and pistons can obviously be ar rang-ed otherwise than concentrically. The invention can also be applied to two-stroke engines.

WVhat I claim as my invention and desire to secure by Letters Patent of the United States is 1. A combined internal combustion and compressed air engine comprising in'combination an internal combustion engine, a compressed air engine, a compression chamber common to both engines and a floating piston in said compression chamber for separating the combustion gasesfrom the air.

2. A combined internal combustion and compressed air engine comprising in combination a combustion cylinder, a compressed air cylinder, a pair of pistons, a common compression chamber for both the said pistons, a floating piston in said compression chamber for separating the combustion gases from the air and said compression chamber being formed With a circular shoulder for limiting the travel of the said floating piston.

S. A combined internal combustion and compressed air engine comprising in combi nation a combustion cylinder, a compressed air cylinder, a pair of mutually connected pistons, a common compression chamber for both the said pistons and a floating piston in said compression chamber for separating the combustion gases from the air.

4. A combined internal combustion and compressed air engine comprising in combination a pair of concentrically arranged cylinders, a pair of pistons, one of the said pistons being annular, a common compression chamber for both the said pistons and a disk piston in said compression chamber for separating the combustion gases from the air.

5. A combined internal combustion and compressed air engine comprising in combination a pair of concentrically arranged cylinders, a. pair of pistons, one of the said pistons being annular, a compression chamber common to both the said pistons, a disk piston in said compression chamber for separating the combustion gases from the air and means for limiting the travel of said disk piston in said compression chamber.

6. A combined internal combustion and compressed air engine comprising in combination a pair of concentrically arranged cylinders, a pair of mutually connected pistons, one of the said pistons being annular, a compression chamber common to both the said pistons and a disk piston in said compression chamber for separating the combustion gases from the air.

7 A combined internal combustion and compressed air engine comprising in combination a combustion cylinder, a compressed air cylinder, a pair of pistons, a common compression chamber for both the said pistons, a disk piston in said compression chamber for separating the combustion gases from the air, an exhaust port for the combustion gases connecting the common compression chamber With one of the cylinders behind the piston and a valve located in the said port.

8. A combined internal combustion and compressed air engine comprising in combination a combustion cylinder, a compressed air cylinder a pair of pistons, a common compression chamber for both the said pistons, a disk piston in said compression chamber for separating the combustion gases from the air, an exhaust port for the combustion gases connecting the common compression chamber With both cylinders behind their pistons and a valve located in said port.

9. A combined internal combustion and compressed air engine comprising in combination a pair of cylinders concentrically arranged a pair of mutually connected pistons one of the said pistons bemg annular, a compression chamber common to both the said Gomez of this patent may be obtainedfor five cents each, by addressing the Commissioner of Patents. Washington, D. C. 

